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WaveShrink plays pivotal role in analysis of complex bio signals. Wavelet analysis and WaveShrink are the established techniques of statistical research which have to be blended with the analysis of bio signals to provide a high degree of correlation between the desired signal and the observed signal. The multifaceted shrinkage function will obtain lurid responses to the signal perturbed to a very...
Methodologies of deriving phase information from pulsatile intracranial pressure (ICP) signal and characterizing its phase coordination with electrocardiogram (ECG) signal were discussed. The application of ICP phase characterization methods to data from several clinical contexts showed that 1) Unstable periods of ICP were associated with a decreased ICP phase coordination with ECG; 2) Surgical treatment...
Automatic ECG QRS complex detection has been widely studied and used over the past decade. Although QRS complex is the most prominent feature in ECG and can provide useful information about the heart status, other parts of the ECG (P-wave, T-wave, etc) are also significant in determining the health status. Recently, researches for P-wave and T-wave detection algorithms started to appear but a parameter...
The prevalence of atrial conduction defects and sinus node dysfunction increases with age. These age-related changes may play a critical role in establishing the substrate for the development of atrial fibrillation (AF), the most common sustained arrhythmia. Despite the association between atrial arrhythmias and age, little is known of the mechanisms that underlie changes in atrial electrophysiological...
Oetrended fluctuation analysis (DFA), a fractal analysis method which is widely used in heart rate variability (HRV) studies, is used to analyze the scaling behaviour of RR interval series of preterm neonates. The average scaling behaviour, calculated using 30000 RR intervals (3-4 hours), is characterized by a scaling exponent of 1.4 plusmn 0.1 at small scales (n<20) and a smaller exponent of 1...
While biosignal analysis has been a mainstay in many medical applications for a number of decades, notably in cardiology, problems remain in the analysis of high volume data and in comparison among time series. Effective comparisons can determine if the state of a particular patient has changed significantly. These comparisons are useful in both long-term and short-term monitoring. Methods will vary...
Quantitative classification of cardiac arrhythmia is an important tool in ICU and CCU that enables on line monitoring of the cardiac activities. Among fatal arrhythmias are atrial fibrillation (AF), ventricular tachycardia (VT), and ventricular fibrillation that require special algorithms for detection and so for direct medical actions. In this paper, a combined bispectrum and bicoherency classification...
This paper describes an electrical model of the ventricles incorporating real geometry and motion. Cardiac geometry and motion is obtained from segmentations of multiple-slice MRI time sequences. A static heart model developed previously is deformed to match the observed geometry using a novel shape registration algorithm. The resulting electrocardiograms and body surface potential maps are compared...
We present a novel numerical scheme to accurately and efficiently simulate the spatiotemporal electrical propagation for three dimensional heart model. A meshfree particle representation of myocardial volume is first developed, upon which the electrical propagation can be obtained using the element-free Galerkin (EFG) method for the FitzHugh-Nagumo model. This method is based on a sufficient amount...
Recent rapid growth in mobile computing technologies enables telemedicine applications to operate on mobile devices. Our focus is on the design of an integrated electrocardiogram (ECG) beat detector on a personal digital assistant (PDA) platform for the health screening process. The ECG beat detector module will be supported by the PDA version of personal health information management system (PHIMS)...
In result of ECG interpretation process the diagnostic outcome summarizes all the principal information included in the raw recording. This process is investigated in this paper in data flow and data reduction aspects being of particular importance for implementation of distributed ECG interpretation in a wireless network. The detailed analysis of existing software and cardiologists societies guidelines...
Most current Holter devices monitor the ECG for 24 to 72 hours. However, for the accurate diagnosis of many cardiac diseases, especially for the wide variety of asymptomatic cases, continuous ECG monitoring for weeks or even months may be required. In this paper, we focus on the issue of ECG compression during long-term monitoring of the patient. The patient may be at home, at work, or even on a trip...
Wave propagation through the arterial system changes with age and disease state, and mutant mice are often used to study these conditions. We have developed several noninvasive ultrasonic techniques to measure blood velocity and vessel wall motion from which we can calculate aortic pulse wave velocity (PWV), local compliance, impedance spectra, characteristic impedance (Zc), augmentation index (AI),...
Dwarf mouse (deficient in growth hormone and insulin-like growth factor-1) lives about 30% longer than wild type mice. However, very little is known about their cardiovascular physiology. We examined the aortic input impedance in dwarf mice and their wild-type littermates to evaluate any differences. Aortic impedance was determined using pressure and velocity signals which are independent of body...
To investigate the effects of voluntary breathing on respiratory sinus arrhythmia and nonlinearity of heart rate variability (HRV), two kinds of voluntary breathing, speech and breath-holding, were used. The results showed that both types of voluntary breathing diminished the high frequency component of HRV, but speech decreased, while breath-holding enhanced the nonlinearity of HRV as detected by...
A major focus of implantable cardioverter defibrillator (ICD) research has been to reduce the defibrillation shock energy to prolong battery life and provide an enhanced quality of life for the patient. We investigated whether the degree of disorganization (complexity) of the electrogram is correlated with defibrillation shock outcome. The study data sets were recorded using the high voltage leads...
Studies suggest that obstructive sleep apnea syndrome (OSAS) is causally related to abnormal cardiovascular autonomic control in adults, but this has not been established in pediatric OSAS. The goal of this study was to quantify autonomic system dysfunction, as manifested by cardiovascular response abnormalities, in children with OSAS. During wakefulness, we continuously measured the ECG, arterial...
A software approach has been developed for detecting electrocautery noise in the electrocardiogram (ECG) using a wavelet decomposition of the signal. With this approach, a clinical monitoring expert system can be forewarned of potential artefacts in trend values derived from the ECG, allowing it to proceed with caution when making decisions based on these trends. In 15 operations spanning 38.5 hours...
Time/frequency analysis has been extensively used in biomedical signal processing. By extracting some essential features from the electro-physiological signals, these methods are able to determine the clinical pathology mechanisms of some diseases. Fourier spectrum analysis provides a common framework for examining the distribution of global energy in the frequency domain. However, this method assumes...
Recently we have studied the effects of extremely low frequency pulsed electromagnetic fields (ELF-PEMF) on the human biosignals. Electrocardiogram (ECG) and electroencephalogram (EEG) of seventeen healthy volunteers before and after the electromagnetic (EMF) exposure were recorded and analyzed. The root mean square (RMS) values of the recoded data were considered as comparison criteria. EEG results...
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